Efficient Chemical Mechanical Polishing of AISI 52100 Bearing Steel with TiSol-NH 4 Dispersion-Based Slurries

In this paper, chemical mechanical polishing technique was used to prepare an ultra-smooth surface of AISI 52100 steel. It was found that an unexpectedly high MRR of 500 nm/min and a satisfactory surface roughness Ra of 4.0 nm are achieved simultaneously by the synergistic effect of TiSol-NH4 dispersion and H2O2 at near neutral pH 6.0. During the polishing process, the organic base in TiSol-NH4 dispersion and H2O2 can be smoothly transported to the contact area along with uniformly dispersed titanium dioxide as nanocapsules, and then the chemicals for oxidation and complexation are provided to form a reaction film on the AISI 52100 steel surface, while abrasive nanoparticles provide sufficient mechanical force to abrade such a reaction film successively. With the addition of a small amount of H2O2, a porous composite layer composed of iron oxides and iron complex compounds with relatively low mechanical strength can be rapidly formed on the top surface. Therefore, the MRR first dramatically increases. When the H2O2 concentration crosses 0.1 wt% at the MRR summit and further increases, the layer gradually grows compact with high mechanical strength. Therefore, the MRR then gradually decreases. The findings can provide an efficient approach for processing bearing steels with excellent surface integrity.